Tool



V. H. PETERSON.

TOOL.

APPLICATION FlLED FEB.19. 1919.

1,352,68. Patentedept. M, 1920.

f UNITED sra'rss f Y followingis a specification.

l project enough ivIcToB, n. rETERsoN,` oF wAvEaLEY, MASSACHUSETTS.' j

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Specification of Iietters Patent'. Patented Sept 14, 192@I Applica-tion 'mea 'retary 19, i919.. serial No. 273,007.

To all-whom 'it mayconcer: f

Be itknown that I, VICTOR H; PETERSON,

kcitizen of Sweden, residing at Waverley, in the ycounty ofMiddlesex and State of Massachnsetts,

have invented certain new and useful Improvements in Tools, of which the This invention relatesl to 'improvements in milling tools andthe like having removable '1.05

blades. More particularly it relatesto means for the economical use of high lspeedsteel in. such tools. It is, however,vapplicable with advantage to other materials. In an end milling tool. made Iof one'integral piece of metal the successive re-grinding of the blades at the end of the' tool soon wears them dow-n close'to the head, -sothat they do not foruse, and the'life ofthe tool is'then ended'. It is `amongthe objects '.'adjusted and re-set,

r blades subsequently can ofthe inventionl to provideamilling tool which 4when arranged for workshall be solid and stiff, butwhose blades can be removed,

proj ecting farther from/ tool life 'for a renewed and intowhich fresh be inserted, and

the end, giving the succession of grindings,

likewise consumed. By this construction, the higher cost and the greater difficulty ofv workingdthe 'material 4'when the .whole vtool vis lof high speed steel savedV repeatedly with .each rre-setting. The

foi the of the cylindrical portion of thetool being is saved, and this is only high speed steel required is that blades which have the cutting edges.'v t'is a feature of the invention that the blade, thusremovable,'is'secured inplace by a key lwhichin'terlocks with the tool holder, and whose interlocking feature -is made by anextremely simple mechanical process. Another feature' Athat'may be embodied is the interlocking of 'the' blade, ,produced 'by a y similar simple means; and yet another feal,

fsa

ture isthe supporting its holder,

a number of gradations of blade as it is moved forward for re-grinding i and repeateduse,I

providing of a rear abutment the blade against vrecessionin andcapable. of performing this function bypositivemeans. in 'an inlinite position of the tapers radially vto .its

'extends in the direction of the axis faces toward the center of thetool. Thus duringa'nd after being 4the same move or hold the 'bladel/t down solidly in for clearness -with one blade only projecting,

the blade tapering in thickness from one end tothe other; and i vrFig. 5 is asimilar View of the same modiic'ation'with saidblade partly ground away asin usage, and adjusted accordingly. i

Referring to thedrawings, 10 indicatesV the shank lof a tool having a head 11 in which are lcut grooves 12 whose inner. ends v'may be seen`where they run into the reduced neck 13 ofthe tool. The tool portrayed is. an end mill,l1olding blades 14L '.The cutting edges of the. blades are at 14 although these blades .may also be provided with cutting edges at 14 so-as to make a side or cylindrical millingtool, if desired. Each blade is held inplace-bya key 15 which extends alongside of the blade, tapering vin the direction of the axis, from its outer to its'inner end as clearly lseen in Fig. 1'. Itis a feature ofthe invention that the key also outer face, that side of it which forms a part of the periphery smaller than its inner face or side of whicli it is held in place driven in endwise, Anotwitzhstanding that the blade may while at vwork be subjected to powerful stresses tending :to force it radially outward from its setting. The powerful compression arising by wedging thekey and the blade between that'surface of the groove 12 which is indicatedat 12 .in Fig. 2, and that which.Vv is indicated -at 12? labsolutely revents that key from moving outward, by physical obstruction. If the restraint were left merely'to friction, the key might rise a little and when driven in lpull the blade out with it. But owing to the 'cam `action of the surface whose edge is seen at 12, the

key is kept down toward the axis and at time the effect is by friction to the groove 12.

The wall 12 of the groove agamst which the blade is pressed is parallel to the central/e? 2` I vh ll cleavage 'between key` and yblade, but this might be undercut as at 12', Fig. 3,.and the back of the blade shapedcorrespondingly. In that case, the conjoint effect of the groove faces 12- and 12 would be to hold both key and blade down toward the axis, unmovv able radially.

`It will be understood that in the drawing the relative dimensions of key and blade as compared with the tool head are somewhat exaggerated for clearness of showing, above the proportions that mightY well be used in practice.

In manufacture, both key and blade are made from ar steel, and it is a simple operation to 'make both the key and .thel blade tapering radially, with faces thus inclined,

at the endof the tool would, by two or three re-grindings, be ground down so'short that theyl could no longer be used. In .the tool of the invention, when this ,stage is reached, the

blades can be loosened, re-adjusted l.withthe ori inal degree of projection, made tight,

again of one piece.

length of the l blades can be substituted after that is used up; and the tool shank and head continue in service indefinitely.

In this wa'y nearly thewhole In the forms shown in Figs..1'3, the blades.

are assumed to be of uniform thickness from end to end. In such a case, they are heldI A against endwise recession only b, friction.

This indeed is thought to be enou nary uses to which theJtool mayIie put; but for special solidity the blades may bemade taperlng endwise,

correspondingly. In that case, when the tool is re-adjuste'd-endwise 'a shim 23 maybe inserted, according to the` thickness. needed. A In using thls form of the tool, there is, consequently, a solid abutment resisting endwise thrusts on the bladesaswellas an` abutrection of the axis; blades set solidlyv A fit removably inthe grooves,

re-ground,as if the vtool were all f blade can be utilized; fresh as shown ink Fig. 4, and the groove 22in which each isset may taper ment resisting radially outward 'pressure 55.

either on the blade or the key. If preferred o the shim may be inserted between key an y. wall, or between key and blade.-

' I claim as my invention v 1. A rotary cutting tool having' a head with grooves extending in the general direction of the axis; blades and keys adapted f to fit removabl inthe ing tapered en Wise an adapted to press its blade laterally toward a wall of the groove; said keysv being also tapered in the radial direction with the smaller dimensionA outward (grooves, each key' beand the groove wall being inclined to corre# spend.A l

2. A rotary cutting tool having a head with grooves extending in the general diand keys adapted to fit removably in the grooves, each key being tapered 'endwise and blade laterally-toward a wall of the groove; said blades bei-ng tapered inthe radial diretionl with the smaller dimension outward and the groove-Wall being inclined to correspond, fitting the blade, with a part of theA groove above the bottom narrower than the base of the blade. M. rotary cutting tool having a head with grooves extending in the general direcl tion of the4 axis;,blades and keys adaptedto each key being tapered.4 'endwise and adapted to press its blade laterally toward a wall of the groove;

adapted lto pleSS its QVsaid blades and said keyseach being tapered l in thelradial directionwith the smaller di'- menS'llltWd, and the groove walls being inclinedtdorrespond. f ,Y 4. A rotary cutting tool having a head with grooves extending in the general-direc- .i

tion ofthe axis; bladesl'andkeys adaptedv to i ft removably in the (grooves, each key being tapered, endwise 'an "adapted to press its ,bladelaterallyztoward a Wallof the groove;

one-of said elements-in each groove being tapered inthe radial direction with the smaller dimension outward; and the groove v wall being inclined togcorrespond.;the blade K being 'tapered end-wise, and there being a Q L;

shim intervening'between'the groove 'wallsv when the blade isi-seated ill-partly withdrawn 1 `1 position.;

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